### Auto-Scrolling Viewport

Using DHTMLLib and CSS, you can add auto-scrolling boxes to your web-page with a minimal amount of code. Using the buttons above, you can change the direction of the marquee.

#### Code

    var sRepeat=null
    function doMarquee(dir, src, amount) {
    	if (window.document.readyState=="loading")
              alert("Please wait until the page is finished loading.")
    	if (amount==null) amount=10
    	switch (dir) {
    	case "up":
    		document.all[src].style.pixelTop-=amount
    		if (-document.all[src].style.pixelTop>=document.all[src].offsetHeight)
    			document.all[src].style.pixelTop=document.all[src].offsetParent.offsetHeight
    		break;
    	case "down":
    		document.all[src].style.pixelTop+=amount
    		if (document.all[src].style.pixelTop>document.all[src].offsetParent.offsetHeight)
    			document.all[src].style.pixelTop = -document.all[src].offsetHeight
    		break;
    	case "left":
    		document.all[src].style.pixelLeft-=amount
    		if (-document.all[src].style.pixelLeft>=document.all[src].offsetWidth)
    			document.all[src].style.pixelLeft=document.all[src].offsetParent.offsetWidth
    		break;
    	case "right":
    		document.all[src].style.pixelLeft+=amount
    		if (document.all[src].style.pixelLeft>document.all[src].offsetParent.offsetWidth)
    			document.all[src].style.pixelLeft = -document.all[src].offsetWidth
    		break;
    	}
    	return false
    }

    function RunMarquee(sDir,sWhich,iAmount) {
      clearInterval(sRepeat)
      if (!iAmount) iAmount=10
      sRepeat = setInterval("doMarquee('"+sDir+"','"+sWhich+"'," + iAmount+")",100)
    }

    function doLoad() {
      setup()
      window.document.all.s1.ondragstart = new Function("return false")
      RunMarquee("right","s1")
    }

    window.onload = doLoad